Drying apparatus



Oct. 28, 1930: J, ULLGREN 1,779,571

DRYING APPARATUS Filed Dec. 17, 1928 f iffarney Patented Oct. 28, 1930 UNITED STATES PATENT'OFFICE J'OHAN DANIEL ULLGREN, OF STOCKSUND, SWEDEN, ASS IGNOB 110 AKTIEBOLAGET KABLSTADS MEKANISKA VERKSTAD, 0F KARLSTAD, SWEDEN, A COMPANY OI SWEDEN IDRYIIN G APPARATUS Application filed December 17, 19528, Serial No. 326,573, and in Sweden November 10, 1927.

The present invention relates to an apparatus for drying granulous and pulverous materials, andmaterials in pieces, such as coal, peat, saw-dust, wood chips, grain, wood pulp, sand, ore, and so forth.

According to the present invention the drying apparatus consists principally of a bowl or the like which is provided at the-top with a charging opening for the material to be dried, and in the bottom with a central opening for the admission of drying gases, and in which there are provided scrapers in a radial or substantially radial direction which are supported and adapted to be rotated by a vertical driving shaft' projecting into the bowl, said scrapers being inclined to the bottom of the bowl and having alongitudinal edge bearing against the same.

The scrapers are put in rotation by the driving shaft with the lower edges of the scrapers directed forwards in the direction of movement, and feed the material to be dried towards the periphery of the stationary bowl where the material is discharged through a suitable opening. During the rotation empty spaces or channels are formed in the material in the rear of the scrapers through which channels the drying gases from the central opening are distributed in the material. The conduit required for admitting the drying gases into the bowl may thus be rigidly secured to the stationary bowl, so that sliding packing surfaces or packing boxes are avoided, which have heretofore caused considerable difiiculties in old dryingapparatus of a similar type. a

In the accompanying drawing an embodiment of the invention is illustrated, Fig. 1 showing .a drying apparatus according to the invention in axial section, and Fig. 2 showing a detail of said apparatus in section and to a larger scale.

The apparatus consists of a round bowl 1 which is covered by a convex cover 2 the central portion of which is traversed by a cylinder 3 which serves as a feed chute for the material to be dried. The bowl 1 is provided at its bottom with a central opening 4 which communicates with a drum 5 closed at the bottom, which is connected to a pipe 6 for admission of drying gases. The drum 5 supports the bowl 1 and rests on a frame 7. Rotatably 'journalled in the frame 7 is a vertical shaft 8 which passes through the bottom of the drum 5, and the upper end of which projects into the bowl 1. Mounted on the end of the shaft 8 projecting into the bowl 1 is a spider 9 the hub 10 of which is slidable but not rotatable on the shaft 8 by means of a key and key-way. Mounted on each arm of the spider 9 is a plate scraper 11 which is freely rotatable on said arm and which extends practically from the opening 4 to the periphery of the bowl 1. The scrapers have inclined positions and bear with one edge against the bottom of the bowl 1. The inclination of the scrapers 11 may be changed, as indicated in Fig. 2, by raising or lowering the spider 9 on the shaft 8. Such raising and lowering 'of the spider 9 is effected' by turning a screw 12 which is screw-threaded into a part 13 rigidly secured to the hub 10.

Secured to the part 13 is a cone 14 which thus rotates with the spider 9 and therefore prevents the material from sticking in the feed chute 3. Said cone extends over the opening 4 so that it conducts the material outwards to the scrapers and prevents it from falling into the drum 5'and the inlet for the drying gases. Secured to the lower side of the cover 2 is a sheet metal cylinder 15 which is concentric with the feed chute 3 and the lower edge of which reaches into the material. Secured to the cover 2 are also two pipes 16 and 17 which lead off the gases collected inside the cylinder 15 and outside the same, respectively.

The a paratus is driven from a suitable source 0 power by means of a bevel gearing 18 so that the shaft 8 and the scrapers 11 are rotated. The material to be dried is charged through the chute 3 and falls into the bowl 1 and is fed by the scrapers 11 outwards to the periphery of the bowl 1, the entire mass being thus kept in motion and being efii ciently traversed by the drying gases flowing from the drum 5, after which the dried material is emptied through a suitabledischar 'e opening 19 in the wall of the bowl. By a justing the scrapers 11 at a suitable angle to the bottom of the bowl 1, which is effected in a manner previously described by means of the screw 12, and which may be accomplished without interrupting the operation, the speed with which the material is discharged may be re ulated whereby an eflicient treatment of dierent materials is rendered ossible.

By tapping the gases by means 0 the pipes 16 and 17 from different points of the bowl it is possible to recover gases having different temperatures and degrees of saturation. and also, for instance when coking in the apparatus, to separate the valuable gases from the steam. It will be understood that it is also possible to provide a plurality of concentric cylinders 15 which separate different zones each of which has its own gas outlet. Below the cone 14 an empty space is formed around the hub 10 of the spider, to which space the gases have free access from the drum 5.- During the rotation an empty space 20, Fig. 2, is formed behind each scraper 11, which space directly communicates with the central empty space below the cone 14, so that the drying gases have a free passage into the material to be dried below and behind the scrapers.

In view of the bowl receiving the material being stationary the conduit serving to admit the drying gases into the apparatus may be rigidly connected 'to the bowl, as previously pointed out, so that sliding packing surfaces, packing boxes, and the like, are eliminated.

The embodiment above described and illustrated in the drawing has only been selected as an example of a suitable manner in which the invention may be carried out, and it will be understood that the same may be modified in severalways without departing from the princi le and scope of the invention as defined in t e following claims.

I claim:

1. In a drying apparatus, the combination of a bowl having an upper central feed opening and a bottom provided with a central opening for admission of drying gases, a vertical rotar shaft in said bowl, and substan tially radially directed scrapers supported by said shaft and extending substantially to said central gas admission opening, said scra ers being inclined to the bottom of said bow and having their lower edges resting against the bottom of the bowl.

2. In a drying apparatus, the combination of a bowl having an upper central feed opening and a bottom provided with a central to the bottom of said bowl and having their lower edges resting against the bottom of the bowl.

3. In a drying apparatus, the combination of a bowl, a cover on said bowl having a central feed 0 ening, walls suspended from said cover and ividing the space below said cover into zones, a gas outlet from each of said zones, said bowl having a bottom provided with a central opening or admission of drying gases, a vertical rotary shaft in said bowl, and substantially radially directed scrapers supported by said shaft, said scrapers being inclined to the bottom of said bowl and having their lower edges resting against the bottom of the bowl.

4. In a drying apparatus, the combination of a bowl, a cover on said bowl having a central feed opening, walls suspended from said cover and dividing the space below said cover into zones, a gas outlet from each of said zones, said bowl havin a bottom provided with a central opening for admission of drying gases, a vertical rotary shaft in said bowl, arms extending substantially radially from said shaft, means for adjusting said arms vertically relatively to the bottom of said bowl, and scrapers pivotally supported by said arms, said scrapers being inclined to the bottom of said bowl and having their lower edges resting against the bottom of the bowl.

5. In a drying apparatus, the combination of a bowl having an upper central feed opening and a bottom provided with a central opening for admission of drying gases, a vertical rotary shaft in said bowl, substantially radially directed scrapers supported by said shaft and extending substantially to said central gas admission 0 ening, said scrapers being inclined tothe ottom of said bowl and having their lower edges resting against the bottom of the bowl, and a cone in said bowl having its point directed upwards and located above said bottom opening intermediate said feed opening and said scrapers.

6. In a drying apparatus, the combmation of a bowl having an upper central feed opening and a bottom provided with a central opening for admission of drying gases, a vertical rotary shaft in said bowl, arms extending substantially radially from said shaft, means for adjusting said arms vertically relatively to the bottom of said bowl, -scrapers pivotally supported by said arms and extending substantially to said central as admission opening, said scrapers being inclined to the bottom of said bowl and having their lower edges resting against the bottom of the bowl, and a cone in said bowl having its point directed upwards and located above said bottom opening intermediate said feed opening and said scrapers.

7. In a drying apparatus, the combination of a bowl, a cover on said bowl having a central feed opening walls suspended from said cover and dividing the space below said cover into zones, a gas outlet from each of said zones, said bowl havin a bottom provided with a central opening or admission of drying gases, a vertical rotary shaft in said bowl, substantiall radially directed scrapers supported by sai shaft, said scrapers being inclined to the bottom of said bowl and having their lower edges resting against the bottom of the bowl, and a cone in said bowl having its point directed upwards and located above said bottom opening intermediate said feed opening and said scrapers.

8. In a drying apparatus, the combination of a bowl having an upper central feed opening and a bottom provided with a central opening for admission of drying gases, a vert1cal rotary shaft in said bowl, arms extending substantially radially from said shaft, means for adjusting said arms vertically relatively to the bottom of said bowl, scrapers pivotally supported by said arms and extending substantially to said central gas admission opening, said scrapers being inclined to the bottom of said bowl and having their lower edges resting against the bottom of the bowl, and a cone in said bowl having its point directed upwards and located above said bottom opening intermediate said feed opening and said scrapers, said cone being attached to said arms so as to rotate with said scrapers.

9. In a drying apparatus, the combination of a bowl, a cover on said bowl having a cen tral feed opening, walls suspended from said cover and dividing the space below said cover into zones, a gas outlet from each of said zones, said bowl havin a bottom provided with a central opening or admission of drying gases, a vertical rotary shaft in said bowl, arms extending substantially radially from said shaft, means for adjusting said arms vertically relatively to the bottom of said bowl, scrapers pivotally supported by said arms, said scrapers being inclined to the bottom of said bowl and having their lower edges resting against the bottom of the bowl, and a cone in said bowl having its point directed upwards and located above said bottom opening intermediate said feed opening and said scrapers, said cone being attached to said arms so as to rotate with said scrapers.

10. In a drying apparatus, the combination of a bowl having an upper central feed opening and a bottom provided with a central opening for admission of drying gases, 2. discharge at the periphery of said bowl, a vertical rotar shaft in said bowl, and substantially radially directed scrapers supported by said shaft and extending substantially to said central gas admission opening, said scrapers being inclined to the bottom of said bowl and having their lower edges resting against the bottom of the bowl.

11. In a drying apparatus, the comblnation of a bowl having an upper central feed opening and a bottom provided with a central opening for admission of dry'n gases, a disc arge at the periphery of saidIwowl, a vertical rotary shaft in said bowl, substantially radially directed scrapers sup orted by said shaft and extending substantia 1V to said central gas admission opening, said scrapers being inclined to the bottom of said bowl and having their lower edges resting against the bottom of said bowl, and a cone in said bowl having its point directed upwards and located above said bottom opening intermediate said feed opening and said scrapers.

12. In a drying apparatus, the combination of a bowl, a cover on said bowl having a central feed opening, walls suspended from said cover and dividing the space below said cover into zones, a gas outlet from each of said zones, said bowl havin a bottom provided with a central opening or admission of drying gases, a vertical rotary shaft in said bowl, arms extending substantially radially from said shaft, means for adjusting said arms vertically relatively to the bottom of said bowl, scrapers pivotally supported b said arms, said scrapers being inclined to t e bottom of said bowl and having their lower edges resting against the bottom of the bowl, and a cone in said bowl having its point directed upwards and located above said bottom openin intermediate said feeding opening and sai scrapers.

J OHAN DANIEL ,ULLGREN. 

